If there are 2 or more flat owners, you are allowed to change the holding type of your flat from joint tenancy to tenancy-in-common (in equal or unequal shares), and vice versa.
If you are already holding the flat under tenancy-in-common, you can also change the proportion of shares held by each owner. The change of holding type or proportion of shares is without monetary consideration. For tenancy-in-common, the shares of ownership of the flat must be in fractions of the same denominator and must add up to one.
You can either appoint your own solicitors to act for you or you can engage HDB to handle the transaction.
Other than the legal status of ownership of the flat, there is no difference in the housing policies governing the lease administration of HDB flats.
To apply for a change in ownership proportion, you can either get a copy of the application form at any HDB Branch or download the application form (PDF, 252 KB) here.
If you wish to transfer the flat ownership without monetary consideration, or pursuant to Court Order, start by finding out the eligibility criteria and types of transfers you can perform.